WIP: Remove the use of concat_alternatives from PrPixelTracking
... and rely on a proper configuration of FetchDataFromFile to provide the resolution of alternatives -- see Brunel!298 (closed), which in turn depends on gaudi/Gaudi!422 (closed)
Also remove use of 'bool' in interface of PrPixelHitManager and
use a tagged_bool
instead
Edited by Gerhard Raven